'QuerySet' object has no attribute ' - Django ORM issue

Question

I have 3 models Material, UOM, BIN_UOM

    @with_author  
    class Material(models.Model):
        version = IntegerVersionField( )
        code = models.CharField(max_length=30)
        name = models.CharField(max_length=30)
        slug = models.SlugField(max_length=80, blank=True)
        description = models.TextField(null=True, blank=True)
        materialuom = models.CharField(max_length=1,
                                  choices=UOM_CHOICES)
        creation_time = models.DateTimeField(auto_now_add=True, blank=True)
        itemgroup = models.ForeignKey(ItemGroup, on_delete=models.PROTECT)
        keywords = models.CharField(max_length=50,null=True, blank=True)
        valid_from = models.DateTimeField(null=True, blank=True)
        valid_to = models.DateTimeField(null=True, blank=True)
        min_quantity = models.DecimalField(max_digits=19, decimal_places=10)
        trigger_quantity = models.DecimalField(max_digits=19, decimal_places=10)
        max_quantity = models.DecimalField(max_digits=19, decimal_places=10)

    @with_author 
    class UOM(models.Model):
        version = IntegerVersionField( )
        code = models.CharField(max_length=30)  
        name = models.CharField(max_length=30) 
        material =  models.ForeignKey(Material) 
        description = models.TextField(null=True, blank=True)



@with_author 
class UOM_BINUOM(models.Model):
    version = IntegerVersionField( )
    UOM =  models.ForeignKey(UOM) 
    BIN_UOM =  models.ForeignKey(BIN_UOM) 
    quantityperunit = models.PositiveSmallIntegerField()
    creation_time = models.DateTimeField(auto_now_add=True,blank=True)

On the input I have my material ID

Using django ORM I want to get all the objects of UOM_BINUOM of my material id.

In SQL :

 Select * from UOM_BINUOM where UOM_BINUOM.uom in (Select uom from UOM where UOM.material = material)

In ORM I am trying to it like this:

uombinuom = UOM.objects.filter(material__in=material_id).uom_binuom_set.all().order_by('-id')

or like this

    material = get_object_or_404(Material, pk=material_id)
    uom = material.uom_set.all().order_by('-id')
    uombinuom = uom.uom_binuom_set.all().order_by('-id')

but getting error

'QuerySet' object has no attribute 'uom_binuom_set'

What I am doing wrong and how can I solve this issue?

Is material_id a list of ids, or a single id?

Alasdair
– Alasdair

2016-05-16 16:46:23 +00:00
Commented May 16, 2016 at 16:46 — Alasdair
– Alasdair, Commented May 16, 2016 at 16:46
material_id is single id

Ilya Bibik
– Ilya Bibik

2016-05-16 16:47:08 +00:00
Commented May 16, 2016 at 16:47 — Ilya Bibik
– Ilya Bibik, Commented May 16, 2016 at 16:47

Alasdair · Accepted Answer · 2016-05-16 16:58:53Z

1

The uom_binuom_set is for a single UOM instance

UOM.objects.get(pk=1).uom_binuom_set.all()

However, you have UOM_BINUOM.objects.filter(...), which is a queryset. As the error says, the queryset does not have the uom_binuom_set method.

You can construct the queryset you want by starting with the UOM_BINUOM model.

uombinuom = UOM_BINUOM.objects.filter(UOM__material=material_id)

Note that since material_id is a single id, you don't need to use __in.

answered May 16, 2016 at 16:58

Alasdair

310k59 gold badges605 silver badges534 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Muhammad Tahir · Accepted Answer · 2016-05-16 16:58:38Z

1

When you do

uom = material.uom_set.all().order_by('-id')

uom is a QuerySet here. uom_binuom_set should be called on single record not QuerySet of records. So you will need to iterate over the uom QuerySet and call .uom_binuom_set.all() for each record.

for record in uom:
   uom_binuom =  record.uom_binuom_set.all()
   # do something with uom_binuom

Or if you want only first records related uom_binuom then

uom_binuom = uom.first().uom_binuom_set.all()

answered May 16, 2016 at 16:58

Muhammad Tahir

5,2221 gold badge25 silver badges40 bronze badges

Collectives™ on Stack Overflow

'QuerySet' object has no attribute ' - Django ORM issue

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related